/*
 * Copyright (c) 2022 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef SPATIAL_SEMAPHORE_H
#define SPATIAL_SEMAPHORE_H

#include <mutex>
#include <condition_variable>

namespace OHOS {
namespace Msdp {
class SpatialSemaphore {
public:
    SpatialSemaphore(int count = 0) : count_(count) {}
    void Signal()
    {
        std::unique_lock<std::mutex> unique(mutex_);
        ++count_;
        if (count_ <= 0) {
            cond_.notify_one();
        }
    }
    void Wait()
    {
        std::unique_lock<std::mutex> unique(mutex_);
        --count_;
        if (count_ < 0) {
            cond_.wait(unique);
        }
    }
private:
    std::mutex mutex_;
    std::condition_variable cond_;
    int count_;
};
} // namespce Msdp
} // namespace OHOS
#endif // SPATIAL_SEMAPHORE_H